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Reverse-Engineering Design Corrects Performance Failures in Laser Flow Cytometers

With numerous developments in medical equipment and software, physicians no longer have to wait three to five days for lab results for accurate and timely blood analysis. Now, specifically designed compact laser flow cytometers (blood analyzers) can conveniently sit on a countertop in the physician’s office and analyze blood samples in fewer than 15 minutes. This technology breakthrough has become the new standard for providing on-site, real time feedback for critical blood analysis.

■ The Challenge: Uncovering the Failure

altA medical device manufacturer discovered that a large supply of its laser flow cytometers had multiple failures that could not be specifically identified by the company’s internal design team. With thousands of unusable units sitting on the shelf, the manufacturer was faced with the difficult decision of scrapping the units and starting over, or determining whether they could be appropriately refurbished at a favorable cost.

Several of the devices were brought to the LightWorks Optics, Tustin, CA, facility for analysis. This provided a unique opportunity for the company’s optical systems engineers to analyze and test the devices in order to identify the root cause of the existing failures, and ultimately, to make recommendations for design updates that would virtually eliminate any future end-use performance failures. Equally challenging would be whether the redesigned device could be produced to meet the manufacturer’s stringent production throughput, acceptance, and budget parameters.

■ The Solution: Advanced Reverse-Engineering

Over the next several weeks, the optical systems engineers at LightWorks applied advanced “reverse-engineering” techniques to identify the underlying cause of multiple failures in the existing devices, which included a lack of manufacturing controls (tolerances and processes), thermally related instabilities in adhesives, mismatched materials, and poor optical alignments. As illustrated in Table 1, each symptom was methodically diagnosed, the root cause determined, and a design correction identified to ensure that a performance failure would not reoccur.

The new design and engineering corrections allowed the machine to accurately focus, count, and measure the blood cells being analyzed with the assurance of long-term alignment stability, regardless of temperature variables.

altWithin a few months, the prototype verification and validation process was completed and the redesigned units were transferred from the operation in Tustin to one of the company’s High-Volume Production (HVP) facilities for production optimization. The manufacturer had stipulated that 50 quality-tested devices be produced each week—leaving very little room for error. The HVP management team set up a dedicated assembly and testing line utilizing LEAN manufacturing techniques to help save on production costs, reduce potential failures, and ensure predictable throughput.

Within six weeks of production set-up, 10 units per day were being successfully produced, with target costs achieved in the first two months of production and throughout the duration of the program. As a result of well-coordinated design engineering and advanced high-volume production teamwork, the medical device manufacturer clearly understood what the device failures were, and received a 90% acceptance rate on the refurbished devices at about one-third of the original cost. This reverse-engineering project resulted in a dramatic cost savings and superior success rates over the original design previously utilized for manufacturing. (See Figure 1)

■ Recent Developments

LightWorks Optics, Inc., has been acquired by II-VI Incorporated, a global leader in engineered materials and optoelectronic components. In addition, LightWorks Optics has merged operations (while maintaining both facilities) with Exotic Electro-Optics, a division of II-VI, resulting in substantial expansion of current capabilities. Exotic Electro-Optics is a leading supplier of state-of-the-art optics, coatings, and assemblies for medical, aerospace, defense, and commercial markets. The new combined company will be operating under the name LightWorks Optical Systems, Inc.

This article was written by Kent Weed, Vice President of Engineering for operations at LightWorks Optical Systems, Inc., Murietta, CA. For more information, visit http://info.hotims.com/45604-167.